atmega128 
  
ATMEGA 128 (AVR) is a microcontroller that has been  equipped for 4Kbyte in its chip EEPROM. EEPROM is separate from the AVR  flash memory, and can be written, read per byte. To be able to access  the EEPROM it needs to manage registers and fuse bit. To prevent errors  in the writing and reading of EEPROM cultivated power supply that is  used quite stable. 
  
When reading the EEPROM microcontroller stops during the four clock  cycles before doing the next command, and to write EEPROM  microcontroller’s clock stopped during the second cycle before doing the  next command.